The invention relates to apparatus for use in the magnetic treatment of liquids particularly, but not exclusively, water for a circulation system.
It is known that certain liquids become so modified when subjected to magnetic flux that material dissolved therein does not precipitate on surfaces with which the liquid comes into contact, or tends less to precipitate on such surfaces. In particular, it is now well known that by subjection to magnetic flux water can be modified in such a manner that solids dissolved therein do not tend or tend less to be precipitated on the internal surfaces of, for example, pipes and heaters which employ circulating water systems for heat removal.
Various apparatus are known for subjecting water and other liquids to magnetic flux. These generally include a flow path through which the liquid, in use of the apparatus, passes and a permanent magnet or electro-magnet which is disposed in the apparatus so that flux traverses the flow path.
There are two aspects to the invention and these are both concerned with the prevention of harm to a magnetic flux source forming part of the apparatus through contact with the liquid to be subjected to the magnetic flux.
In its first aspect, the invention provides an apparatus for use in subjecting a liquid to magnetic flux, which apparatus comprises an inlet for said liquid, an outlet for liquid which has, in use of the apparatus, been subjected to magnetic flux, a fluid flow path connecting said inlet to said outlet, a magnet body comprising a first magnetic pole comprised of a material which is sensitive to contact with said liquid, a second magnetic pole of opposite polarity to and spaced from said first magnetic pole to define a gap between said poles, said magnetic poles being so disposed that, at least in use of the apparatus, lines of magnetic flux pass therebetween and, in so doing, traverse at least part of said fluid flow path, and means which protect said first magnetic pole from contact with said liquid in use of the apparatus. In its second aspect, the invention provides an apparatus for use in subjecting a liquid to magnetic flux, which apparatus comprises an inlet for said liquid, an outlet for liquid which has, in use of the apparatus, been subjected to magnetic flux, a fluid flow path connecting said inlet to said outlet, a magnet body having first and second magnetic poles of mutually opposite polarity and spaced apart to define a gap between said poles, said magnetic poles being so disposed that at least in use of the apparatus, lines of magnetic flux pass therebetween and traverse at least part of said fluid flow path, and means to direct and liquid, in use of the apparatus, through said gap to said outlet without traversing the axial extent of the magnet body.
The expression "sensitive to contact" means that the first pole is susceptible, at least under operating conditions, to chemical and/or electrolytic attack, and consequent damage, by the liquid or a component thereof.
The expression "magnet body" means a body which, at least under operating conditions, acts as a source of the magnetic flux and it will be appreciated that the magnet body may be constructed from one or more ferromagnetic components and may conveniently be a permanent magnet but may alternatively be an electromagnet which generates flux only when supplied with electric current. In preferred embodiments of the invention, the apparatus will include means to direct the liquid, in use of the apparatus, through the gap to the outlet without traversing the axial extent of the magnet body and will also include means which protect the first magnetic pole from contact with the liquid in use of the apparatus.
The means which protect the first magnetic pole may conveniently comprise non-magnetic stainless steel or brass. It is also possible to protect the first magnetic pole by means of a film, for example a film of plastics material or an applied coating of, for example, a resinous composition such as a varnish.
Conveniently, the fluid flow path is defined in a housing made of non-magnetic material and provided with an aperture to said fluid flow path in which aperture said magnet body is received. For example, the magnet body may comprise a first member of which the first magnetic pole forms part, and a second member of which the second magnetic pole forms part, the two members being in magnetically conductive connection with each other and separated by a magnetically permeable separator which extends into the gap between the poles and protects the first magnetic pole from contact with the liquid in use of the apparatus. The magnet body may conveniently comprise an annular cylinder provided with a core piece in magnetically conductive connection with the cylinder, and a member which is in magnetically conductive connection with the cylinder and which defines the gap with an axial extremity of the core piece. The member referred to may conveniently comprise an annular element including a first portion in magnetically conductive connection with the cylinder and a second portion which terminates in one of the magnetic poles, the second portion defining an aperture in the element which aperture lies in the fluid flow path.
In preferred forms of the invention, the first and second magnetic poles are of such size and shape as to focus the magnetic flux in the gap. For example, the core piece referred to above may be chamfered at its axial extremity, for example as shown in FIG. 3 of the drawings. Another preferred feature of apparatus according to the invention is a construction in which the flow path is so oriented with respect to the gap that, in use of the apparatus, liquid flows through said gap and intersects in a substantially perpendicular fashion the lines of flux passing between the first and second poles.